Re: [PATCH v6 4/7] xen/arm: configure dom0less domain for enabling xenstore after boot

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 13 May 2022, Julien Grall wrote:
> On 13/05/2022 02:23, Stefano Stabellini wrote:
> > On Wed, 11 May 2022, Julien Grall wrote:
> > > > If dom0 is mandatory yes, we should still make sure that this code
> > > > cannot be
> > > > reached so an ASSERT would be nice here at least in case someone tries
> > > > to
> > > > activate this code without dom0 (which might happen when we will push
> > > > the
> > > > serie for static event channels).
> > > 
> > > I am fine with an ASSERT().
> > 
> > I added an ASSERT(hardware_domain).
> 
> Just to clarify and avoid a round trip. The ASSERT() is not sufficient here.
> We also need to forbid the user to set xen,enhanced when the HW domain is not
> NULL, at least until Rahul's pre-allocated event channel series.
> 
> This check would have to be done when parsing the configuration. The ASSERT()
> would be here to ensure that if someone is reworking the parsing, it would get
> caught nicely rather than a NULL dereference.

Thanks for avoiding a roundtrip. I added a check when parsing device
tree if xen,enhanced is specified but dom0 is missing. Initially I wrote
it as a "panic" but then I changed it as a regular printk. I am OK
either way in case you prefer otherwise.